EARLY EMBRYONIC DEVELOPMENT OF THE NASOLACRIMAL DUCT OF THE COMMON QUAIL COTURNIX COTURNIX (PHASIANIDAE, GALLIFORMES)

The development of the nasolacrimal duct was studied in the common quail (Coturnix coturnix) at 6,7,8,9 and 10 days of incubation. The nasolacrimal duct started its development, as one or two solids ectodermal cords of cells (the nasolacrimal duct primordium) from superior conjunctival fornix of the lower eye lid. After that, the nasolacrimal duct primordium proceeded in its ontogeny forming bifurcated structure (anterior, posterior rami). Cavities appeared within duct and two rami as development proceeded. The nasolacrimal duct approached the olfactory organ gradually, and then it fused with its wall.